Fresno, CA Environmental Rules: Flood Elevation Requirements (2026)

1," the state code's base flood elevation and freeboard rule for the lowest floor. That section was repealed and re-enacted by Ordinance 2025-041 (adopted September 25, 2025, effective October 31, 2025), replacing an earlier version tied to the 2005 flood ordinance. Section 11-628 extends the same benchmark to nonresidential construction: the lowest floor must either be elevated to the § 11-627 standard, or the building must be floodproofed below that elevation so it is "watertight with walls substantially impermeable to the passage of water," with structural components able to resist hydrostatic and hydrodynamic loads, and a professional engineer or architect must certify to the Flood Plain Administrator that the standard is met.

Manufactured homes get the same elevation trigger: § 11-633 requires homes placed or substantially improved in mapped A-zones to be elevated so the lowest floor reaches "the elevation specified under Section 11-627," secured to an anchored foundation. Subdivisions over 50 lots or 5 acres must identify Base Flood Elevations and certify lowest-floor and pad elevations to the Flood Plain Administrator under § 11-632, and any site filled above the BFE needs a FEMA Letter of Map Revision Based on Fill. Documentation of these elevation certifications is kept on file for public inspection under § 11-619.